Asthma afflicts as many as 39 million Americans and some 4,000 will die of the disease each this year. The goal of this Phase I SBIR proposal is to design, develop, build, and test a novel, cooled laser catheter for effecting Bronchial Thermoplasty in a safe and efficient manner. Bronchial Thermoplasty is a relatively new term which refers to destruction of the muscular mucosa surrounding the bronchioles (tubular airway branches in the lungs) in an effort to defeat asthmatic airway constriction for the most severely afflicted patients. Recently, a radio-frequency (RF)-based device was introduced onto the market, but the device has drawbacks including the destruction of the endothelium which can result in worsening of condition in the short term. We believe that significant improvement may be obtained by employing a novel laser-based catheter system developed by BioTex for intraluminal sub-surface ablation which may result in faster therapeutic administration and should avoid destruction of the endothelial lining and the resulting "sloughing" process currently associated with RF- based methods. PUBLIC HEALTH RELEVANCE: The goal of this Phase I SBIR project is to develop a laser balloon catheter for reduction of symptoms in severe asthma by destroying the smooth muscle tissue which leads to asthma "attacks". We will develop prototype catheters and test them in large animal subjects to verify performance in preparation for clinical studies in Phase II.